# Summing Raster cells to equal circles with specific sum using ArcMap? [closed]

I have application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] OR 47.746 users per square km).

I have taken these points and turned them into an interpolated raster surface with a cell size of 50mx50m. Now I can see the whole user density across the map. I accounted for the cell size by dividing the km-sq density by 400 (there are 400 50m by 50m cells in 1 square km). So now each cell reports the number of users (like .25 users per sq 50m).

1. Now what I want to do is tell ArcMap to create circles that maximize coverage of the map and have within them a total of 150 users. So I want ArcMap to sum up the cell values to equal 150 but within a circular area.
2. I also want to minimize the number of circles that are needed to cover the whole map.

I'm stuck. I've tried block statistics, but I can't designate that I want users to be added together, only the size of the areas. At then end of this I want a map with circles of 150 users each.

Any ideas?

## closed as unclear what you're asking by PolyGeo♦Sep 19 '16 at 2:22

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• This sounds like it's a very similar problem to gis.stackexchange.com/questions/144392/… the comment by ChrisW is very helpful. Although your data is slightly different the underlying method sounds the same. If not, can you draw a picture showing what you want. – Michael Stimson May 6 '15 at 23:57
• Similar yes, but a bit different since this is dealing with raster. The basic problem is the same - there's an arbitrary number of ways to group pixels to total a value, even if you're trying to minimize groups. I'm assuming you have Spatial Analyst? I suspect something in the Neighborhood toolset might be helpful. Circles don't lend themselves to full coverage and minimal overlap. And I'm not sure about what your purpose is, but getting counts out of densities is going to be an approximation at best given the need to assume uniform distribution. – Chris W May 7 '15 at 1:55
• Have you considered calculating sum in a circular moving window via Focal Statistics (Spatial Analyst)? If needed you could limit the results to max = 150 using Con. – Aaron May 7 '15 at 11:23
• Most of this post sounds like an attempt at solving some unstated problem in geographic analysis--perhaps identifying territories or regions of influence or something like that. Because it is complicated, not very well defined, and appears likely to be difficult to implement, consider changing the question to one that describes your analytical objectives and solicits ideas for how to achieve them. Otherwise you might be stuck implementing good ways to perform an inefficient or (worse) incorrect calculation. – whuber May 7 '15 at 18:42